Mating electrical connectors typically employ pairs of inter-engaging pin and socket terminals for interconnecting a plurality of circuits or wires through the mated connectors. The pin and socket terminals are often called male and female terminals.
One type of female terminal includes a generally rectangular socket or receptacle at its mating end for receiving a generally rectangular pin or male terminal therein. The mating end is formed by an elongate body defining top and bottom walls and opposite cantilevered sidewalls. Such terminals are conventionally stamped and formed from sheet material and the top and bottom walls may have open seams or slits, whereby the opposite walls can flex about axes generally perpendicular to the elongated axis of the terminal. This type of flexing creates certain problems.
For example, dimples are typically formed on opposite sidewalls at the mating end of the female terminal to establish more positive contact with the inserted male pin or terminal. Preferably, a pair of longitudinally spaced contacting dimples is formed on each flexible sidewall. In order to achieve a stable electrical connection between the female terminal and the male pin, the dimples in the sidewalls of the female terminal need to exert consistent and equal forces on the pin. Unfortunately, since the sidewalls flex about axes that are generally perpendicular to the longitudinal axis of the terminal, and since the dimples in each pair are spaced longitudinally of the terminal, unequal pressure is typically applied by the contacting dimples to the male terminal when the male terminal is fully inserted. This leads to further complications when the dimples are plated with a highly conductive material, such as gold. Uneven wear then occurs on the dimples, and the gold plating can actually wear off one of the contacting dimples before the other. In some instances the endmost dimple in each longitudinally spaced pair may not contact the pin at all.
Dimples generally provide good engagement between the male pin and the female terminal, but only make electrical contact at a very small point. Because of this relatively small contact area provided by such dimples between the sidewalls of the female terminal and the surfaces of the male pin, heat can build up at the small interface areas provided by the dimples. Such small contact areas are not effective at removing any heat buildup.
Yet another problem with the foregoing terminal structure is that the inserted male terminal tends to seat in the bottom of the female terminal instead of centering therein. With the relatively small contact area that dimples provide, centering of the male terminal becomes important.
U.S. Pat. No. 5,437,567 to Peterson, and which is assigned to the same assignee as the present invention, utilizes a sidewall arrangement in which the male terminal is biased upwardly and is therefore better centered in alignment with the contacting dimples of the female terminal. However, it remains desirable to provide a greater and more effective electrical contact area between the male pin and the female terminal than that provided by a pair of dimples on each of opposing sidewalls. With greater contact areas, centering of the male terminal becomes less critical.
This invention is directed to solving the problems identified above and to satisfying the need for an improved elongated female electrical terminal.